Generally the objectives of both present and future research are concerned with a better understanding of physiological phenomena on a cellular and molecular level. In the past, considerable emphasis was placed on the study of catecholamines and other hormones at the biochemical level resulting in the eventual clarification of some aspects of the biological role of cAMP. These studies will include mechanism of action of adenylate cyclase from various sources. The role of the feedback regulator (FR) for controlling cellular cAMP levels and hormone action will be the main goal of our research. The biological action, occurence and destruction of FR in different tissues will be studied in future years. The first priority is still the purification and characterization of FR.